Landing gear method and apparatus for braking and maneuvering

ABSTRACT

Aircraft landing gear comprised of a wheel hub motor/generator disks stack, includes alternating rotor and stator disks mounted with respect to the wheel support and wheel. The wheel hub motor/generator can provide motive force to the wheel when electrical power is applied, which may be applied prior to touch-down thus decreasing the difference in relative velocities of the tire radial velocity with that of the relative velocity of the runway thus greatly reducing the sliding friction wear of said tire. After touchdown the wheel hub motor/generator may be used as a generator thus applying a regenerative braking force and/or a motorized braking action to the wheel. The energy generated upon landing maybe dissipated through a resistor and/or stored for later use in providing a source for motive power to the aircraft wheels for the purpose of taxiing and ground maneuvers of said aircraft.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The Invention relates to aircraft landing gear and, more specifically toan integrated wheel hub motor/generator, regenerative braking and/ormotorized braking method for an aircraft landing gear system, whichreduces wear of the braking system and the associated tires whileimproving stability of said aircraft and reducing the need formaintenance due to wear.

2. Related Art

It is known in the field of aircraft wheel and brake assemblies toprovide a non-rotatable wheel support, a wheel mounted to the wheelsupport for rotation, and a brake disk stack using friction braking toconvert rotatory motion of said disks into friction heat energy whichcreates wear of said disks. Various brake actuation configurations andmethods are known, as in U.S. Pat. Nos. 4,381,049, 4,432,440, 4,542,809,4,567,967, 4,596,316, 4,865,162 and 6,615,958.

The current state of the art for providing braking systems for aircraftuses stators and rotors, which are forced into physical contact witheach other thus generating friction heat that introduces wear of theassociated disks and requires periodic maintenance to replace the wornparts.

The primary drawback of carbon disk brakes of the latest designs is thata greater volume of carbon material is needed to absorb the same amountof heat energy as that of steel disk brakes. Another drawback of carbondisk brakes is the diminished braking capacity due to moisturecontamination of the carbon surfaces due to rain and the highreplacement cost after they are worn.

Furthermore, aircraft are required to maneuver within the definedtaxies, runways and terminals. One such requirement is the 180-degreeturn that places an upper limit on the aircraft allowed for a particularrunway based upon the width of the runway and the ability of saidaircraft in conducting a 180-degree turn there on within the physicalwidth of said runway. Current landing gear provides limited abilities toperform such 180-degree turns.

One significant concern in aircraft brake design is the dissipation ofkinetic energy of aircraft within the braking system of the landing gearsystem during landing and rejected takeoff conditions. Ultimately, it isthe rolling friction present between the tires and the landing surface,which slows the aircraft, thus brake capacity requirements are basedupon maximum landing weight of the aircraft and the rolling friction.Braking systems of the prior art are relatively inflexible with respectto the manner in which they generate the required braking force.

OBJECTS OF THE INVENTION

Accordingly, it is an object of the invention to provide an improvedsystem and method for braking and maneuvering in landing gear ofaircraft.

It is a further object of the invention to overcome the limitations anddrawbacks associated with prior art systems for braking and maneuveringin landing gear of aircraft.

A further object of the invention is to reduce wear of the componentsinvolved in the landing gear and braking system, add stability to theaircraft structure, and increase reliability, while reducing the neededmaintenance associated with current friction braking systems.

It is a further object of the invention to reduce the need for frictionbrake disks within the landing gear of aircraft.

It is yet a further object of the invention to provide a system andmethod for recovering kinetic energy from aircraft and convert suchenergy into electrical power.

It is a still further object of the invention to provide a system andmethod for aircraft landing gear, which permits a reduced turn radiusfor the aircraft.

Another objective is to reduce the wear of the tires of said aircraftdue to sliding friction wear due to touchdown by closely matching thelanding gear tires radial velocity with that of the relative groundvelocity such that when touchdown occurs the difference in velocity isgreatly minimized, thus greatly reducing the sliding friction wear ofsaid tires associated with the touchdown of the landing gear tires withthe runway landing surface. This sliding friction, which is present inthe current state of the art, creates an associated wear that affectstire performance thus affecting safety.

A further object is to provide a means of motive force for the purposeof conducting taxiing and ground maneuvers of said aircraft, whichcontributes to increased efficiency, maneuverability, stability andsafety of said aircraft.

A further object is to provide a means of motive force for the purposeof assisting in takeoff, which reduces the required takeoff distance forthe aircraft, which also contributes to increased efficiency,maneuverability, stability and safety of said aircraft.

SUMMARY OF THE INVENTION

The present invention provides a unique means of aircraft brakingwherein the use of regenerative braking and/or motorized braking isapplied in a manner, which creates advantages over prior art frictionbraking systems. This is accomplished by integrating a wheel hubmotor/generator within the wheel and axle structures wherein the brakingaction is provided for by the magnetic torque interactions of the statorand rotor disk sections of said wheel hub motor/generator. Kineticenergy of said aircraft is converted into electrical power, which may bedissipated through a resistor and/or stored for later use when theaircraft is taking off, taxiing and performing other ground maneuvers,or may be used at the time of landing to increase the effectiveness ofthe electromagnetic braking system by instituting the use of motorizedbraking action, thus increasing the overall efficiency of the brakingsystem and adding stability and safety to said aircraft.

Moreover, it has been discovered that other features present haveapplications to reduce landing gear tire wear of aircraft by using thewheel hub motor/generator as a motor prior to landing to match the tireradial velocity with that of the relative ground velocity such that whentouchdown occurs that there is minimal difference in the two velocitiessuch that sliding friction wear is greatly minimized thus improving lifetime of landing gear tires thus increasing the performance of saidlanding gear tires, which adds to the controllability and safety of saidaircraft. There is an added benefit in that when the landing gear wheelsare motorized in flight they provide a gyroscopic stabilizing effect,which dramatically stabilizes the aircraft depending upon the speed ofrotation of said landing gear wheels.

In one embodiment, a wheel hub motor/generator disks stack includesalternating rotor and stator disks wherein each rotor disk is coupled tothe wheel for rotation and each stator disk is coupled to the axleand/or torque tube for support that is static in relation to the tirerotation. In a preferred embodiment the wheel hub motor/generatorfunctions as a brake by means of generator action also known asregenerative braking wherein magnetic torque interactions between therotor disk and stator disk sections apply a braking force to the wheeland tire assembly and the electrical power generated is stored for lateruse.

The wheel hub motor/generator may have mounted thereon a plurality ofassociated stator and rotor disk members which may be activated ordeactivated individually, sequentially or in unison with the applicationof an electrical current or generation of electrical current in varyingdirections depending upon the need for motor and/or regenerative and/ormotorized braking action. In one such case electromagnetic braking isapplied by using associated rotor and stator disks as a generator andfrom which the output power from the stator is applied to another statordisk in such a manner as to increase the braking effect of theassociated rotor of said other stator disk, thus accomplishing motorizedbraking action or motoring of a disk or disks which is acting as agenerator within the same, or other wheel hub motor/generator, diskstack as that of the generating disk or disks.

The method of motor/generator electrical interconnections of differentstator disk or disks within the same, or other wheel hubmotor/generator, disk stack or motorized braking method as disclosedherein can be varied in numerous combinations of generator disk or disksand motor disk or disks within the present invention and is unique inthe area of disk type axial flux motor/generators and offers flexibilityin aircraft applications by allowing for the electrical and/or physicaladdition of disk or disks or removal of disk or disks based upon theaircraft landing weight and/or landing gear design needs. Thiselectrical interconnection of disks in which any disk within the wheelhub motor/generator disk stack may act as a motor or as a generator orin any combination thereof is known as motorized braking method asproposed within the present invention, which adds flexibility to thedesign of aircraft landing gear. Incorporating the use of disk typeaxial flux motor/generators greatly reduces design cost due to thisflexibility in motoring and braking of said motor/generator.

As noted above, one concern in aircraft brake design is the dissipationof kinetic energy of aircraft within the braking system of the landinggear system during landing and rejected takeoff conditions; ultimately,it is the rolling friction present between the tires and the landingsurface which slows the aircraft, and thus brake capacity requirementsare based upon maximum landing weight of the aircraft and the rollingfriction. The method of motorized braking in accordance with theinvention introduces flexibility in generating the required brakingforce that is lacking in the present state of the art braking systems,and allows for more efficient designs in that an overloaded aircraft canincrease the amount of braking capacity by means of altering theelectrical connections through switching controls thus increasing thesafety of the aircraft.

Furthermore, by implementing the use of disk type axial flux wheel hubmotor/generators within the landing gear said aircraft is able to reducethe turn radius in which a 180-degree turn may be accomplished by meansof motoring one set of landing gear in one direction and motoring theother set of landing gear in the opposite direction, this method ofturning thus allows said aircraft to complete a 180-degree turn within asmaller turning radius as opposed to that of the current state of theart landing gear, due to the fact that the center of rotation of thepresent invention is located between the main landing gear on the centerline of said aircraft and not at the intersection of the lines extendingfrom the axes of the nose gear and landing gear as with current state ofthe art landing gear. This feature provides for reduced runway surfacewear due to the lack of need to lock up the brakes on the pivotinglanding gear assembly and eliminates the associated wear of the tires ofthe pivoting landing gear assembly due to the sliding friction, which ispresent in the current state of the art.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is explained in greater detail below with reference to anexemplary embodiment that is illustrated in the accompanying figures.

FIG. 1 is a cross sectional view of an embodiment of a disk type axialflux wheel hub motor/generator in accordance with the invention.

FIG. 2 is a flow chart representing one possible implementation ofswitching controls used to implement the landing gear method inaccordance with the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1. Shows the cross sectional view of a possible disk stack axialflux type wheel hub motor/generator used to accomplish the neededelectromagnetic braking and/or motoring of the landing gear wheels.

The rotors 1 are coupled to the wheel 4 and rotate with the wheel 4. Thestator disks 2, which may be constructed of an electrically conductivematerial, are coupled to the shaft 3 and/or central torque tube, and arestationary with respect to the wheel in which said disks areelectrically isolated from each other except through availableelectrical connections (not shown). The rotor disks 1, which may beconstructed of an electrically conductive material or may be constructedof permanent magnets, are coupled to the wheel 4. The wheel 4 issupported by means of a bearing set 5, which may be comprised of inboardand outboard bearing sets or a sleeve, air, or magnetic type bearing.

In the preferred embodiment, prior to touchdown the wheel 4 is motorizedby applying power with a radial flow of electrical current through thestator disk 2 which generates an axial magnetic flux field whichinteracts with the axial magnetic flux field of the rotor disk 1permanent magnets which are of a high energy density such as neodymiumwhich are substantially located within the rotor disk 1 with an axialflux orientation in which all said permanent magnets are in the samevector direction. This embodiment develops a magnetic torque between therotor disk 1 and stator disk 2, which causes the wheel 4 to experience amotor action. The stator disk 2 and/or rotor disk 1 may be comprised ofaluminum, which may be coated with copper, which may be further coatedwith silver and/or may be comprised of any other alloy combination suchas beryllium, copper and/or conductive polymer for increased strength.The electrical connections required are not shown, as the provision ofelectrical connections is well known. Such electrical connection mayinclude, e.g., rolling contacts and/or sliding carbon brushes.Alternatively, a brushless design may be used in order to accomplish themotor/generator action due to axial magnetic flux interactions describedherein.

FIG. 2 shows the flow of the switching controls system signals and powersignals used to accomplish the needed signals to control motoring and/orbraking of the aircraft landing gear wheel hub motor/generator within abrushless design.

In the case of providing motor action to the wheel hub motor/generatorthe Hall effect sensors 1 are used to indicate the position of thepermanent magnets wherein the magnets are alternating north and southpoles with the flux aligned axially. The position information of therotor disk is sent to the processor 3 for proper timing of controlsignals which are sent to the optical isolators 5 which are then sent tothe polyphase brushless commutation driver control 10 which appliespower from the power storage device and/or onboard power supply 9 to thestator field coils within a single stator disk 12 such that a motoraction is produced either in the forward or reverse directions dependentupon the input from the user brake and motoring input control 7 whichprovides information to the processor 3 through the optical isolators 5such as to initiate user input for forward or reverse motor actionwithin the wheel hub motor/generator and the input from the parkingbrake controller 4 to the processor 3 is such that it indicates whetherthe parking brake friction braking system is engaged or not. An alarm 2will activate if the parking brake is engaged and user input from theuser brake and motoring input control 7 is initiating motor action. Ifthe parking brake is disengaged the processor 3 will allow motor actionin the forward or reverse direction as per the user input from the userbrake and motoring input control 7.

In the case of providing generator action from the wheel hubmotor/generator an electrical power connection is provided for from thestator field coils within a single stator disk 12 to the regenerativebraking and polyphase rectification control 11 and as the relativemotion occurs between the stator and rotor sections a polyphase powersignal is generated within the wheel hub motor/generator stator coilsand this power signal is sent to the regenerative braking and polyphaserectification control 11 which converts the varying polyphase powersignal into a DC signal based upon control signals generated from theprocessor 3 which is dependent upon the input user control signals fromthe user brake and motoring input control 7. If the processor controlsignal is such that power storage and/or power dissipation is requiredthen the DC power signal is sent from the regenerative braking andpolyphase control 11 to the power storage device and/or onboard powersupply 9 for later use and/or sent to a power dissipation resistor 13for the dissipation of the generated electrical power. The regenerativebraking and polyphase rectification control 11 may also be used toprovide polyphase electrical power to the motorized braking control 6which is controlled by processor 3 control signals in applying motorizedbraking commands as described within the preferred embodiment whereinpolyphase power signals are applied to stator field coils of otherstator disk 8 within the same or other wheel hub motor/generator diskstack such as to supply electrical power to stator field coils of otherstator disk 8 which are experiencing generator action thus increasingthe braking effect by motoring the disk in the opposite direction tothat of the rotor rotational direction thus providing for a motorizedbraking effect which is unique in the area of brushless axial fluxmotors and generators.

Brushless axial flux motors and generators are well known in which theuse of segmented rotor and stator sections are used. Variations ofbrushless axial flux motors and generators are taught within thefollowing U.S. Pat. Nos. 4,223,255, 4,567,391 4,585,085, 6,046,518,6,064,135 6,323,573 B1, 6,617,748 B2 and 6,633,106 B1 also within thefollowing application publications US 2003/0159866 A1 and US2002/0171324 A1. Any axial flux type motor/generator also known as diskor pancake motors may be used incorporating the method of motorizedbraking as described within the patent including those which have yet tobe issued patents. The rotors or stators are generally composed ofpermanent magnet segments such that there exist alternating north andsouth poles with the flux aligned axially. The rotor or stator sectionsgenerally consists of stator or rotor coils within a single stator orrotor disk attached to the stator or rotor disk with hall effect sensorswhich are also attached to the stator or rotor disk, which is alsosegmented as such to align the coil sets with that of the permanentmagnets used within the rotor or stator. The stator or rotor coilswithin a single disk require controlled application of currents to saidcoils from a polyphase brushless commutation driver control such as tocause motor action. The control signals applied to such polyphasebrushless commutation driver controls are generated from a processorthrough optical isolation using position information provided for by theHall effect sensors. Such brushless motors may also be used inregenerative braking to supply electrical current by means of generatoraction and the electrical current path is provided for by means ofelectrical switching controls wherein the electrical power generated isstored for later use via a control system.

The possible forms of axial flux motors and/or generators may besummarized as follows. Generally the windings may be either stationaryor rotary in which the windings may be incorporated into the followingstructures. One such possible structure is a slotted laminated orcomposite iron core material with the windings located within slots.Another possible structure is a slotless structure in which the windingsare wound into coils those are embedded within an ironless structure ormay be wound around a laminated or composite iron core material. Afurther possible structure is a solid structure in which inducedcurrents circulate within a solid conducting material, which may or maynot be a ferromagnetic material. Windings for a disk structure may be ofprinted circuit type and/or stamped from copper sheet and/or may be ofcopper windings wound into individual coils, which may or may not be ofa litz wire construction.

Uses

The instant after touch down the wheel hub motor/generator which is usedas a motor may be converted so as to be used as a generator bydiscontinuing the application of power to the stator disk and drawingpower from said stator disk due to the generator action that takes placewhen the magnetic field of the rotor disk is in relative motion withthat of the stator disk such relative motion is due to the kineticenergy of the aircraft and by using well-known electrical switchingaction and controls such as electronically controlled switches such asIGBT's and/or electromechanical type relays such that generatedelectrical power may be stored and/or dissipated and/or applied to otherstator disk which increases the braking effect by means of motorizedbraking.

The generated electrical current from the stator disk may be stored onthe airplane by means of battery, capacitor banks or other suitableelectrical power storage devices such as a gyro and/or toroidal coil orcoils that are electrically connected to the stator disk through theimplementation of control electronics and/or physical contacts, thusallowing for dissipation and/or storage of electrical power generatedfor the purpose of supplying electrical power for later use.

Electromagnetic braking in its motorized braking method is preferablyapplied by using associated rotor and stator disk or disks as agenerator whose output is applied to another stator disk or disks whichthen produces a motor action which is in direct opposition to therotational direction of the wheel which generates a motorized brakingaction that exceeds that of regenerative braking alone, thus decreasingthe braking distance and increasing the safety of the aircraft.

The method of motorized braking is preferably accomplished by two means.The first means is by the generated electrical power from one statordisk due to the relative motion of the associated rotor disk that may beapplied to another stator disk within the wheel hub motor/generator diskstack in such a manner as to increase the braking effect by motoring theother associated rotor disk of said other stator disk in the oppositedirection, thus accomplishing motorized braking or motoring of a disk ordisks within the same or other wheel hub motor/generator disk stack asthat of the generating disk or disks. The second means uses storedand/or onboard generated and/or external electrical power such thatpower is applied to the stator disk through provided electricalconnections such that motor action is applied to the rotor disks in theopposite direction of rotation of the wheel thus accomplishing motorizedbraking or motoring of disk or disks within the wheel hubmotor/generator. The two means above may be combined to produce thedesired braking.

The axial flux wheel hub motor/generator may be used to provide formotor action to the aircraft landing gear wheels thus providing agyroscopic stabilization effect to the aircraft. In a landing sequencethe aircraft would deploy the landing gear and then apply a forwardrotary motion to the aircraft landing gear wheels which will stabilizethe aircraft due to the gyroscopic effect thus increasing the stabilityand safety of the aircraft.

Another embodiment uses eddy current braking as opposed toelectromagnetic braking wherein the rotor disk are constructed ofaluminum, aluminum alloy, steel, copper, beryllium, silver or anycombination thereof of various constructions and the stator disk may beconstructed as described above in the electromagnetic case of theprevious preferred embodiment wherein the braking is accomplished byapplying electrical current to the stator disk such that the magneticfield of the stator disk induces eddy currents within said rotor disksuch that there is developed a magnetic torque which generates a brakingaction upon the wheel of said aircraft.

Any combination of the above embodiments may be used in addition to thatof friction braking systems currently used, thus increasing the life andaiding the usefulness of the friction braking system as well as reducingthe associated maintenance cost by reducing the rate of wear and thenumber of friction disk required. Cooling systems used for frictionbraking systems may also be employed in the above embodiments andembodiment combinations if needed.

In the case of a landing event the pilot deploys the landing gear andthe landing gear wheel hub motor/generator is applied power by the pilotinput controls such as to cause a forward rotation of the landing geartires. The rotational velocity of a landing gear tire for a 130-mile perhour landing event for a typical 747 aircraft would be approximately 48rad/sec in order to match the tire and ground velocities thus greatlyreducing the sliding friction wear of said tires. The instant aftertouchdown the control systems are used to store the generated electricalpower from the wheel hub motor/generator thus providing regenerativebraking. Then a few moments later the stored energy is applied to thewheel hub motors via the control system to cause motor action in theopposite direction than that of the rotational direction of the rotorthus providing for motorized braking. To cause the aircraft to come to acomplete stop friction type brakes would be used which would also beused to apply a parking brake force to the landing gear wheels.

In the case of a takeoff event the pilot would initiate input controlssuch as to cause a forward rotation of the landing gear tires and powerup the jet engines. This would cause the aircraft to travel down therunway faster than with the use of the jet engines alone thus reducingthe needed runway distance for takeoff for a particular aircraft.

In the case of rejected takeoff all braking systems would engage in amanor such as to maximize the braking capacity of the aircraft.

In the case of the 180-degree turn ground maneuver the pilot wouldinitiate input controls such as to cause one set of landing gear to bepowered in the forward direction and the other set of landing gear to bepowered in the opposite direction thus accomplishing the turning of saidaircraft which is terminated under the control of the pilot.

In the case of aircraft carrier operations power supplied is from andexternal source of power via an attachment to the aircraft such as thatused to propel or launch aircraft off an aircraft carrier. The means ofelectrical connection can be a direct physical contact connector or anon-contact type that employs the use of magnetic induction to transferthe energy from a ground track to the aircraft. In such animplementation in commercial aircraft ground tracks could beincorporated into the runways of an airport such as to allow for powertransfer and/or provide for a means in which aircraft control personnelcould directly control ground movements of aircraft by controlling thepower supplied to the aircraft wheel hub motor/generator thus increasingthe level of control for the aircraft control personnel.

Although exemplary embodiments of this invention have been described, itin no way limits the scope within this invention. Those skilled in theart will readily appreciate that any modifications are possible and areto be included within the scope of this invention as defined in thefollowing claims. In the claims, where means plus function clause areused, they are intended to cover the structural concepts describedherein as performing the recited function and not only structuralequivalents but also equivalent structures.

The method of the invention as described herein above in the context ofthe preferred embodiments is not to be taken as limited to all of theprovided details thereof, since modifications and variations thereof maybe made without departing from the spirit and scope of the invention.For example, the principles of the invention in their broader aspectsmay be applied to other motive and/or braking systems for electricvehicles such as trains, buses, trucks, cars, and boats or otherelectrically driven devices, which require braking.

1. An integrated wheel/hub motor generator and electromagnetic brakingsystem for aircraft landing gear, comprising: a nose gear and a mainlanding gear, at least one of the nose gear or the main landing gearcomprising: a nonrotational base portion configured to connect to anairframe of the aircraft; a wheel connected to and rotatable withrespect to the base portion about a rotational axis; a plurality ofstators connected to the base portion; a plurality of rotors connectedto the wheel and configured to rotate with respect to said stators;wherein each of said pluralities of stators and rotors is configured togenerate a magnetic flux; and wherein said pluralities of stators androtors are configured so that interaction of their magnetic fluxescauses at least one of: converting electrical energy to rotationaltorque energy of the wheel, and converting rotational torque energy ofthe wheel to electrical energy of a magnitude suitable for use todecrease the rotational velocity of said wheel.
 2. The integratedwheel/hub motor generator and electromagnetic braking system foraircraft landing gear in accordance with claim 1, further comprisingfriction-type brakes connected to the base portion and configured tobrake the wheel relative to the base portion in a blended braking systemwherein magnetic braking is blended with conventional friction-type diskbrakes.
 3. The integrated wheel/hub motor generator and electromagneticbraking system for aircraft landing gear in accordance with claim 1,wherein said pluralities of stators and rotors are configured so thatinteraction of their magnetic fluxes causes: converting electricalenergy to rotational torque energy of the wheel, and convertingrotational torque energy of the wheel to electrical energy.
 4. Theintegrated wheel/hub motor generator and electromagnetic braking systemfor aircraft landing gear in accordance with claim 1, wherein saidpluralities of stators and rotors comprise conducting wire within carbonmaterial configured so that interaction of their magnetic fluxes causes:converting electrical energy to rotational torque energy of the wheel,and converting rotational torque energy of the wheel to electricalenergy.
 5. The integrated wheel/hub motor generator and electromagneticbraking system for aircraft landing gear in accordance with claim 4,wherein said conducting wire comprises a high temperaturesuperconducting wire.
 6. The integrated wheel/hub motor generator andelectromagnetic braking system for aircraft landing gear in accordancewith claim 1, wherein said plurality of stators comprise high energydensity permanent magnets within carbon material and said plurality ofrotors comprise conducting wire within carbon material configured sothat interaction of their magnetic fluxes causes: converting electricalenergy to rotational torque energy of the wheel, and convertingrotational torque energy of the wheel to electrical energy.
 7. Theintegrated wheel/hub motor generator and electromagnetic braking systemfor aircraft landing gear in accordance with claim 6, wherein saidconducting wire comprises a high temperature superconducting wire. 8.The integrated wheel/hub motor generator and electromagnetic brakingsystem for aircraft landing gear in accordance with claim 1, whereinsaid pluralities of stators and rotors are configured so thatinteraction of their magnetic fluxes causes converting substantially allof the wheel's rotational energy into electrical energy and then intoheat energy by the formation of eddy currents in at least one of saidpluralities of stators and rotors.
 9. The integrated wheel/hub motorgenerator and electromagnetic braking system for aircraft landing gearin accordance with claim 1, wherein said plurality of rotors comprisehigh energy density permanent magnets within carbon material and saidplurality of stators comprise steel, configured so that magnetic fluxesof the permanent magnets cause eddy currents to be generated within astator, causing a magnetic drag torque energy to be generated within thewheel to dissipate the rotational energy of the wheel.
 10. Theintegrated wheel/hub motor generator and electromagnetic braking systemfor aircraft landing gear in accordance with claim 9, wherein theplurality of rotors comprise conducting wire and the plurality ofstators comprise a solid conducting material conducive to generation ofeddy currents when power is applied to said wire.
 11. The integratedwheel/hub motor generator and electromagnetic braking system foraircraft landing gear in accordance with claim 9, wherein the pluralityof stators comprise conducting wire and the plurality of rotors comprisea solid conducting material conducive to generation of eddy currentswhen power is applied to said wire.
 12. The integrated wheel/hub motorgenerator and electromagnetic braking system for aircraft landing gearin accordance with claim 1, wherein the aircraft landing gear comprisestwo wheels connected to and independently rotatable with respect to thebase portion about the axis, wherein each of the two wheels isassociated with a portion of the plurality of stators and a portion ofthe plurality of rotors.
 13. The integrated wheel/hub motor generatorand electromagnetic braking system for aircraft landing gear inaccordance with claim 1, wherein at least one of said plurality ofstators comprises electrically conductive wires and is configured togenerate a first magnetic flux substantially parallel to said axis whencurrent passes through said wires, wherein at least one of saidplurality of rotors comprises a permanent magnet configured to generatea second magnetic flux substantially parallel to said axis, and whereinthe landing gear is configured to cause the wheel to rotate when saidcurrent passes through said wires by a magnetic torque interaction ofthe first and second magnetic fluxes.
 14. The integrated wheel/hub motorgenerator and electromagnetic braking system for aircraft landing gearin accordance with claim 1, wherein each of said plurality of statorscomprises electrically conductive wires and is configured to generate afirst magnetic flux substantially parallel to said axis when currentpasses through said wires, wherein each of said plurality of rotorscomprises a permanent magnet configured to generate a second magneticflux substantially parallel to said axis, and wherein the landing gearis configured to cause the wheel to rotate when said current passesthrough said wires by a magnetic torque interaction of the first andsecond magnetic fluxes.
 15. The integrated wheel/hub motor generator andelectromagnetic braking system for aircraft landing gear in accordancewith claim 1, wherein at least one of said plurality of rotors compriseselectrically conductive wires and is configured to generate a firstmagnetic flux substantially parallel to said axis when current passesthrough said wires, wherein at least one of said plurality of statorscomprises a permanent magnet configured to generate a second magneticflux substantially parallel to said rotational axis, and wherein thelanding gear is configured to cause the wheel to rotate when saidcurrent passes through said wires by a magnetic torque interaction ofthe first and second magnetic fluxes.
 16. The integrated wheel/hub motorgenerator and electromagnetic braking system for aircraft landing gearin accordance with claim 1, wherein each of said plurality of rotorscomprises electrically conductive wires and is configured to generate afirst magnetic flux substantially parallel to said axis when currentpasses through said wires, wherein each of said plurality of rotorscomprises a permanent magnet configured to generate a second magneticflux substantially parallel to said axis, and wherein the landing gearis configured to cause the wheel to rotate when said current passesthrough said wires by a magnetic torque interaction of the first andsecond magnetic fluxes.
 17. The integrated wheel/hub motor generator andelectromagnetic braking system for aircraft landing gear in accordancewith claim 1, wherein said plurality of stators and said plurality ofrotors are configured in a plurality of stator-rotor sets, each setcomprising at least one stator and at least one rotor.
 18. Theintegrated wheel/hub motor generator and electromagnetic braking systemfor aircraft landing gear in accordance with claim 17, wherein, in eachof said stator-rotor sets, at least one of said at least one stator andat least one rotor comprises electrically conductive wires configured togenerate a magnetic flux substantially parallel to said axis whencurrent passes through said wires, wherein each of said stator-rotorsets is independently operable as at least one of a motor and agenerator depending on a voltage applied across said wires.
 19. Theintegrated wheel/hub motor generator and electromagnetic braking systemfor aircraft landing gear in accordance with claim 18, furthercomprising: a processor connected to said stator-rotor sets; and anelectrical device comprising at least one of an electrical energystorage device and an electrical energy dissipation device, wherein theprocessor is configured to connect and disconnect the stator-rotor setsto and from each other and to and from the electrical device.
 20. Theintegrated wheel/hub motor generator and electromagnetic braking systemfor aircraft landing gear in accordance with claim 19, wherein theelectrical device comprises a battery.
 21. The integrated wheel/hubmotor generator and electromagnetic braking system for aircraft landinggear in accordance with claim 19, wherein the electrical devicecomprises a capacitor.